Today's thoughts (regarding cancer)

What is growth fraction?

• It is the percentage of cells  in a tumour mass that are actively dividing.

What is doubling time?

• It is the amount of time  it takes for a tumour to double in size ( in Burkitt lymfoma it can be as short as 24 h, in some adenocarcinoma it could be up to 200 days or longer).

The rate of growth slows  as the tumour increases in size, due to limits imposed by tumour microenvironment. Small tumours or micro metastasis might to be more sensitive to chemotherapy, this is the idea that lies behind  adjuvant chemotherapy (chemotherapy that is given after an initial intervention that is designed to cut-reduce the tumour bulk and remove all macroscopic disease)

Resources: Oncology at a glance, Graham G. Dark